A Spy Phage? (VP882 Should be Renamed VP007)

It’s not often I find stories about any of the other “-omes” outside the microbi-ome, so I was pretty excited to find a big piece of news this week related to the virome.

Microbiologists at Princeton University discovered a phage (remember, bacteriophages are viruses that kill bacteria) that actually spies on the conversations of bacteria to know when the time is ripe for attack.[i]

According to the lead scientist, Dr. Bonnie Bassler, viruses can only make 1 decision:  to either remain inside the host “under the radar,” or to replicate itself and attack other nearby hosts.  If the virus attacks too soon and there are not enough viable hosts in close enough proximity, the virus and its offspring will just die.[ii]

These researchers though have discovered that this particular phage (VP882) has evolved to “listen” to the chemical crosstalk between bacteria, signaling that they are in a crowd.

Dr. Blasser discovered years ago that bacteria communicate and sense each other’s presence, so that they know there are enough of them to mount a successful attack.  Discovering that a bacteriophage can spy on them and understand that message, so that it too could pick an optimal time for its own attack, was a stunning discovery:  this virus remains dormant until bacteria have reproduced enough to mount an attack, and then it swoops in, destroying the invading bacterial army.

What’s truly remarkable about this is that these are radically different organisms, from different biological kingdoms.  The fact that this virus can understand the “language” of another species is astounding.  To boot, while most viruses can only attack 1 particular kind of cell (for example, the flu virus only infects lung cells), so far VP882 has shown it can recognize, and optimize an attack on, cholera, salmonella and E.coli.

This is a huge step forward in creating therapeutic phages to treat bacterial infections:  phages are totally targeted in their attack and thus, would spare the commensal bacteria of the gut.

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[i] Justin E. Silpe, Bonnie L. Bassler. A Host-Produced Quorum-Sensing Autoinducer Controls a Phage Lysis-Lysogeny Decision. Cell, 2018; DOI: 10.1016/j.cell.2018.10.059

[ii] https://www.sciencedaily.com/releases/2018/12/181213142206.htm